Speed control mechanism



Ma.y 27, 1941.

w. c, sco'r'r SPEED CONTROL MECHANISM 2 Sheets-Sheet 2 Filed Aug. 14,1956 INVENTOR mV 5 6 I. w W

ATTORNEY Patented May 27, 1941 UNITED STATES PATENT OFFICE SPEED CONTROLMECHANISM Walter C. Scott, Plainfleld, N. J.

Application August 14, 1936, Serial No. 96,056

12 Claims.

This invention relates to speed control mechanism, and ,has for its mainobject and feature means to coordinate the speed of two motors.

In the accompanying drawings the invention is shown in one form inwhich:

Fig. l is a more or less diagrammatic view, partly in section, showingtwo associated motors, in the present form gas engines, and interrelatedcontrol mechanism for same;

Fig. 2 is an enlarged detail view in section of a coupling or clutchused in connection with the invention;

Fig. 3 is a transverse sectional view substantially on the plane of line3-3 of Fig. 2;

Fig. 4 is a longitudinal sectional view through the control mechanismsubstantially on the plane of line 4-4 of Fig. l; and

Fig. 5 is a transverse sectional view substantially on the plane of line5-5 of Fig. 4.

A and B indicate two motors associated in some way and intended to runeither at substantially the same speed or at some other predeterminedrelative speed such as two to one. In the present instance, motors A andB drive propeller shafts I and 2 of a ship or an aeroplane and maytherefore run at equal speed or at such slightly different speed as willtend to avoid undue vibration. 3 and 4 indicate the carbureter throttlesof thetwo motors, which throttles are movable in opposite directions toopen and close them, and which are urged into closed position by springs5 and 6. Suitable operating means for the throttles are provided,consisting, in the,

case of throttlew4, of member I and handle 8 pivoted at 9, and, in thecase of throttle 3 of two slidably related members, one of whichi is arod connected to handle 'Il pivoted at l2, and the other of which is asleeve 13 connected to throttle 3 and adapted to abut, under theinfluence of spring 5, against abutment member l4 on rod I0. HandlesBand II can be operated independently but it is preferred to connectthem by means of rods l and I6 and adjustable turnbuckle so that byoperating either handle the two throttles can be operated in unison.

0 indicates a speed control mechanism, to be presently described,responsive to the speed of both motors A and B and in turn controllingthe position of at least one of the throttles. In the present instancethis control is accomplished by means of a coupling or clutch C soconstructed and arranged that a movement of control element Z of controlmechanism 0 is transmitted to sleeve l3, but that, on the'cont'rary, amovement of sleeve I3 is not transmitted to control element Z. Thecoupling consists here ofa housing l8 loosely mounted on sleeve l3 andmovable by bifurcated member l9 that engages pins 20 on the housing.Member I9 is here in the form of a bell-crank pivotally supported at 2iand will cause cam 24 to clutch ball 23 against sleeve l3 therebyimparting a movement to the latter independently of rod l0 so that theposition of throttle 3 is slightly changed in that it is opened to agreater extent. When the upper arm of bellcrank I9 is moved to the right(in Fig. l) cam 24 will no longer clutch ball 23 against sleeve l3 andspring 5 will be free to return sleeve I3 against abutment l4. It willfurther be observed that manipulation of say handle II in eitherdirection will cause sleeve l3 to slide freely through housing l8 andthe motion will not be transmitted to coupling C, control element Z orcontrol mechanism 0. Considering the action of clutch C more in detail,it will be observed that, as stated above, cam 24 is movable with aswell as independently of housing l8. Prior to the time that lever l9moves to the left (in Fig. 1), bearing member 24a of said cam will be incontact with collar l8a of housing l8 and, as the latter moves to theleft (in Fig. 2), cam 24 will at first move with housing l8 and willengage ball 23 holding the latter stationary and front wall l8b willmove away from the ball. At this time there is no movement of member l3.The movement of housing l8 now continues toward the left while cam 24stands still until the rear wall of said housing l8 abuts bearing member24a of cam 24. This causes cam 24 to clutch ball 23 so hard that itcarries member l3 with it. When lever is is moved to the right (in Fig.1), it carries housing 3 with it while cam 24 momentarily remainsstationary until collar 18a moves it. Meanwhile movement of member [3 tothe right (in Fig. 2) under the action of spring 5 keeps ball 23 againstcam 24. The movement of member l3 continues until the end of said memberstrikes collar. l4. The movement of housing l8 continues to the right(in Fig. 2) for a short additional distance but, as member l3 no longermoves, ball 23 will not follow cam 24 and will be completely released.

The construction of control mechanism 0 may take many forms. In thepresent instance it takes the form shown in my application Ser. No.60,423, filed January 23, 1936, now Patent No. 2,119,247 of May 31,1938, and consists of two control members X and Y mounted to rotateindependently of each other at all times on shaft 25. Member X isprovided with a series of arcuate and tapering grooves 26 for thereception of balls 21, and member Y is provided with a continuoussurface 28 engaging balls 21. Members X and Y rotate in the samedirection which in this case is with the shallow end of grooves 26leading and the deep end of the grooves trailing. At least one of saidmembers, here Y, is slidably as well as rotatably mounted on shaft 25. Aspring 29 urges member Y toward member X. It will now be understood thatso long as member Y does not exceed the speed of member X, balls 21 willremain in the deep part of grooves 26 but that so soon as the speed of Yexceeds that of X, balls 21 will travel into the shallow end of grooves26 whereby member Y will be moved sidewise against the tension of spring29 thereby imparting a movement to control element Z pivotally supportedat 30, which element in turn transmits its motion to coupling C in themanner previously described. When member Y slows down to the speed of Xor falls below it (or when, what amounts to the same thing, the speed ofX is accelerated above that of Y), balls 21 return to the deep end ofgrooves 26 and spring 29 moves member Y toward X,-contro1 element Z isreturned to its original position and coupling C declutches. Member X ishere rotated from shaft 1 by suitable transmission means consisting inthis instance of sprockets and chain 3|. Member Y is similarly drivenfrom shaft 2 by means of sprockets and chain 32.

The gearing or transmission is so proportioned that when motors A and Brun, at the desired relative speed, control members X and Y will run atequal speed. The parts can be so adjusted that, when either handle 8 orII is actuated, throttle 3 will be opened to a slightly less extent thanthat desired. This will cause control member Y to run slightly fasterthan X and therefore member Y will move sidewise thereby actuatingcontrol element Z and will cause coupling C to move sleeve l3 to openthrottle 3 to a slightly greater extent. If member X is accelerated toequal the speed of member Y, coupling C will be declutched wherebyspring 5 will return sleeve l3 against abutment member l4 and member Xwill be decelerated. This acceleration and deceleration will, repeatitself whenever conditions warrant it, and consequently the two motorswill operate substantially at the desired relative speed.

I claim:

1. The combination with a carbureter throttle movable in oppositedirections, of a spring to urge said throttle toward its closedposition, means controlled by the operator to move said throttle intoits open position, and a speed control mechanism and connections to movesaid throttle toward its open position.

2. The combination with a carburetor throttle movable in oppositedirections, of meanscontrolled by the operator to move said throttle ineither direction, a speed control mechanism, and connections including acoupling to transmit a movement of the speed control mechanism in onedirection only to the means controlled by the operator but incapable oftransmitt ng a movement of the means controlled by the operator to thespeed control mechanism.

3. The combination with a carburetor throttle movable in oppositedirections, 01' a spring to urge said throttle toward its closedposition, means controlled by the operator to move said throttle intoits open position, a speed control mechanism, and connections includinga coupling to transmit a movement of the speed control mechanism in onedirection only to the means controlled by the operator but incapable oftransmitting a movement 01' the means controlled by the operator to thespeed control mechanism.

4. A control means for a motor including: two slidably related membersmovable in unison and one of which is capable of independent movement,and means to move said independently movable member including a couplingthat is incapable of transmitting a movement of the member it moves.

5. A control means for a motor including: two slidably related members,an abutment element carried by one of said members against which theother member abuts, a spring to urge the members into abutting relation,and means to move one of said members independently of the otherincluding a coupling that is incapable of transmitting a movement of themember it moves.

6. A control means for a motor including: an operating member movable inopposite directions to control the motor, a control mechanism andconnections to move the operating member in one direction but not in theother, said control mechanism being unresponsive to movements of theoperating member in either direction.

7. A control means for a motor including: an operating member movable inopposite directions to control the motor, a control member, couplingmeans between said members responsive to transmit a movement of thecontrol member to the operating member in one direction but not in theother and incapable of transmitting a movement of said operating memberto the control member.

8. In a system of speed control, the combination with the carbureterthrottles of two motors, of a speed control mechanism controlled by therelative speed of the motors, means controlled by said speed controlmechanism to vary the position of at least one of said throttles, andmeans to vary in unison the position of said throttles independently ofthe speed control mechanism.

9. The combination with a carbureter throttle movable in oppositedirections, of speed controlled means to move said throttle in onedirection but not in the other, and means controlled by the operator tomove said throttle in either direction without transmitting the movementto the speed controlled means.

10. In a system of speed control, the combination with the carbureterthrottles of two motors, of a speed control mechanism controlled by therelative speed of the motors, means controlled by the operator to movesaid throttles in either direction, and connections including a couplingto transmit a movement of the speed control mechanism to the meanscontrolled by the operator to vary the position of at least one of saidthrottles but incapable of transmitting a movement of the meanscontrolled by the operator to the speed control mechanism.

11. In a system of speed control, the combination with the carbureterthrottles of two motors, of means controlled by the operator to movesaid throttlesin opposite directions, speed control motors, a speedcontrol mechanism controlled by the relative speed of the two motors,and connections from said speed control mechanism to move the operatingmember in one direction but not in the other, said control mechanismbeing unresponsive to movements of the operating member in eitherdirection.

W'ALTER C. SCOTT.

